System, method and computer-readable medium for locating physical phenomena

ABSTRACT

A method, system and computer product for detecting the location of a deformation of a structure includes baselining a defined energy transmitting characteristic for each of the plurality of laterally adjacent conductors attached to the structure. Each of the plurality of conductors includes a plurality of segments coupled in series and having an associated unit value representative of the defined energy transmitting characteristic. The plurality of laterally adjacent conductors includes a plurality of identity groups with each identity group including at least one of the plurality of segments from each of the plurality of conductors. Each of the plurality of conductors are monitored for a difference in the defined energy transmitting characteristic when compared with a baseline energy transmitting characteristic for each of the plurality of conductors. When the difference exceeds a threshold value, a location of the deformation along the structure is calculated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patentapplication Ser. No. 10/992,440 entitled STRUCTURES INCLUDING NETWORKAND TOPOLOGY FOR IDENTIFYING, LOCATING AND QUANTIFYING PHYSICALPHENOMENA, filed on Nov. 17, 2004, which is a divisional of U.S. Pat.No. 6,889,557, entitled NETWORK AND TOPOLOGY FOR IDENTIFYING, LOCATINGAND QUANTIFYING PHYSICAL PHENOMENA, SYSTEMS AND METHODS FOR EMPLOYINGSAME, issued on May 10, 2005, and this application is acontinuation-in-part of co-pending U.S. patent application Ser. No.10/825,804 entitled METHODS AND SYSTEM FOR PIPELINE COMMUNICATION, filedon Apr. 14, 2004.

GOVERNMENT RIGHTS

The United States Government has rights in the following inventionpursuant to Contract No. DE-AC07-05-ID14517 between the U.S. Departmentof Energy and Battelle Energy Alliance, LLC.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a network and topology fordetecting physical phenomena and for locating and quantifying the same.More particularly, the present invention relates to the use of a codednetwork implemented within a structure for detecting physical changeswithin the structure.

2. State of the Art

It is often desirable to detect and monitor physical changes within astructure. For example, it may be desirable to monitor pipes or otherconduits for leaks or indications thereof so as to prevent collateraldamage from such leaks. Similarly, it may be desirable to monitor thedeformation of other structures, such as, for example, a bridge, abuilding, or even individual structural components of such facilities inorder to determine actual or potential failures therein.

Various systems have been used to detect such physical changes. Forexample, one system used for detecting leaks in a pipe or other conduitis disclosed in U.S. Pat. No. 5,279,148 issued to Brandes on Jan. 18,1994. The Brandes patent teaches a system which includes a first pipefor carrying a liquid medium and a second pipe which is coaxiallylocated relative to the first pipe such that it encompasses the firstpipe. A filler material is disposed in the annulus formed between thefirst and second pipes. Probes are inserted into the filler material ateach end of the set of pipes to measure resistance of the fillermaterial at each end of the pipe system relative to ground as well asbetween the two ends of the pipe system. Initial resistance measurementsare used as a baseline value for future monitoring. Detection ofsignificant deviation in the resistance measurements indicates a leakfrom the first pipe (i.e., the liquid medium has infiltrated the fillermaterial thereby changing the resistivity/conductivity thereof). Thechange in resistance between the ends of the coaxial pipes as well asthe change in resistance at each end of the coaxial pipes relative toground may then be utilized to determine the location of the leak bycomparing the ratio of the respective changes in resistance.

While such a system may be effective in detecting a leak within a pipe,it may also be cumbersome and expensive to implement, particularly sincea second outer pipe is required to encapsulate the filler material aboutthe first, liquid carrying pipe. Such a system would likely be difficultand cost prohibitive in retrofitting an existing layout of pipes orother conduits for leak detection. Also, the Brandes patent fails todisclose whether such a system would be effective for structuresextending significant distances (i.e., several miles or longer) and withwhat resolution one may determine the location of a detected leak.

Further, such a system is only practical with respect to detecting afailure in a liquid carrying structure. If a transported liquid is notavailable to infiltrate the surrounding filler material andsignificantly change the electrical properties thereof, no detectionwill be made. Thus, such a system would not be applicable to detectingfailure in various members of bridges, buildings or other suchstructures.

Another method of detecting fluid leaks includes the use of time domainreflectometry (TDR) such as is disclosed in U.S. Pat. No. 5,410,255issued to Bailey on Apr. 25, 1995. TDR methods include sending a pulsedown a transmission line and monitoring the reflection of such pulses. Achange in the time of arrival or the shape of a reflected pulseindicates a leak based on, for example, a change in the structure of thetransmission line and/or its interaction with the leaking medium.However, to implement a TDR system with, for example, a pipeline whichextends for significant distances, special processing algorithms mayhave to be developed to enable rejection of spurious data for pipejoints or other discontinuities. Also, the types of transmission lineswhich may be used in such a TDR system may be restricted based on theirelectrical characteristics including the dielectric and resistivitycharacteristics of any insulation associated with such transmissionlines.

Yet another approach detecting fluid leaks is disclosed in U.S. Pat. No.4,926,165 to Lahlouh et al. on May 15, 1990. The Lahlouh patent teachesthe use of two spaced apart conductors separated by a swellable membersuch that no electrical path exists between the two conductors in normaloperating conditions. Upon occurrence of a leak, the swellable memberswells to conductively contact the two conductors, creating anelectrical short therebetween as an indication of a leak. However, sucha device requires relatively complex construction including properconfiguration of the conductors and swellable members. Additionally, theintrusion of a liquid other than that which may potentially leak from apipe or conduit could trigger false indications of such leaks.

Additionally, as with the aforementioned Brandes patent, the method anddevice of the Lahlouh patent may only be used for detecting leaks in aliquid carrying structure and is not capable of detecting failures inother structures.

In view of the shortcomings in the art, it would be advantageous toprovide a method and system for detecting, locating and quantifyingphysical phenomena such as leaks, strain and other physical changeswithin a structure. Further, it would be advantageous to providemonitoring of such physical phenomena to track potential failures of astructure for purposes of preventative maintenance.

It would further be advantageous to provide a method and system fordetecting physical phenomena which is inexpensive, robust, and which maybe implemented in numerous applications and with varying structures.

BRIEF SUMMARY OF THE INVENTION

In accordance with one aspect of the invention a method of detecting thelocation of a deformation of a structure is provided. The methodincludes locating deformation of a structure including a plurality oflaterally adjacent conductors configured for attachment thereto. Thelocating method includes baselining a defined energy transmittingcharacteristic for each of the plurality of laterally adjacentconductors attached to the structure. Each of the plurality ofconductors includes a plurality of segments coupled in series and havingan associated unit value representative of the defined energytransmitting characteristic. Furthermore, the plurality of laterallyadjacent conductors includes a plurality of identity groups with eachidentity group including at least one of the plurality of segments fromeach of the plurality of conductors. Each of the plurality of conductorsis monitored for a difference in the defined energy transmittingcharacteristic when compared with a baseline energy transmittingcharacteristic for each of the plurality of conductors. When thedifference exceeds a threshold value, a location of the deformationalong the structure is calculated.

In accordance with another embodiment of the present invention, a systemfor locating deformation of a structure is provided. The system includesa network configured for attachment to a structure including a pluralityof laterally adjacent conductors. Each of the plurality of conductorsincludes a plurality of segments having an associated unit valuerepresentative of a defined energy transmission characteristic. Theplurality of laterally adjacent conductors includes a plurality ofidentity groups with each identity group including at least one of theplurality of segments from each of the plurality of conductors. Also,each segment within the identity group exhibits an associated unit valuesuch that the unit values of each identity group may be represented by aconcatenated digit string of the unit values and wherein each identitygroup exhibits a unique concatenated digit string relative to each otheridentity group. The system further includes a computing systemconfigured to baseline a defined energy transmitting characteristic foreach of a plurality of laterally adjacent conductors, monitor each ofthe plurality of conductors for a difference in the defined energytransmitting characteristic when compared with a baseline energytransmitting characteristic for each of the plurality of conductors, andcalculate a location of the deformation along the structure when thedifference exceeds a threshold.

In accordance with a further embodiment of the present invention, acomputer-readable medium having computer-executable instructions thereonfor executing a locating method for identifying the location ofdeformation of a structure is provided. The method includes locatingdeformation of a structure including a plurality of laterally adjacentconductors configured for attachment thereto. The locating methodincludes baselining a defined energy transmitting characteristic foreach of the plurality of laterally adjacent conductors attached to thestructure. Each of the plurality of conductors includes a plurality ofsegments coupled in series and having an associated unit valuerepresentative of the defined energy transmitting characteristic.Furthermore, the plurality of laterally adjacent conductors includes aplurality of identity groups with each identity group including at leastone of the plurality of segments from each of the plurality ofconductors. Each of the plurality of conductors is monitored for adifference in the defined energy transmitting characteristic whencompared with a baseline energy transmitting characteristic for each ofthe plurality of conductors. When the difference exceeds a thresholdvalue, a location of the deformation along the structure is calculated.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing and other advantages of the invention will become apparentupon reading the following detailed description and upon reference tothe drawings in which:

FIG. 1 is a schematic of a network and topology used in detecting aphysical phenomena according to one embodiment of the present invention;

FIG. 2 is a schematic view of a portion of the network shown in FIG. 1;

FIG. 3 is a partial cross-sectional view of a structure incorporating anetwork according to an embodiment of the present invention;

FIGS. 4A and 4B are partial sectional views taken along the linesindicated in FIG. 3;

FIG. 5 is a partial cross-sectional view of a structure and anassociated network for detecting physical phenomena according to anaspect of the present invention;

FIG. 6 is a cross-sectional view of a structure incorporating anassociated network including a plurality of conductors angularlydisplaced about a circumference of the conduit, in accordance withanother embodiment of the present invention;

FIG. 7 is block diagram of a computing system configured to locate adeflection in a structural member, in accordance with an embodiment ofthe present invention; and

FIG. 8 is a flowchart of a method for locating a deflection in astructural member, in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a network 100 is shown for detecting a physicalphenomena according to an exemplary embodiment of the present invention.The network 100 includes a transmitter 102 operatively coupled with afirst conductor 104 and a second conductor 106 at first adjacent endsthereof. The two conductors 104 and 106 are each coupled at an opposingend to a receiver 108. The conductors 104 and 106 may be any of a numberof different energy transmitting mediums, including, for example,conductive traces, semiconductive traces or optical fibers and, thus,the term “conductors” is used herein to encompass any such energytransmitting medium. Similarly, while the terms “transmitter” and“receiver” are used herein, such are used in the generic sense of beingable to transmit energy (including, for example, electrical energy orlight energy) and receiving and detecting the transmitted energy.

The first and second conductors 104 and 106 are positioned laterallyadjacent one another and are defined to include a plurality of segments110A-110D and 112A-112D respectively which, for sake of convenience,shall be referred to herein with respect to the exemplary embodiments asresistance segments. As with the various terms discussed above, the term“resistance segment” is used generically to indicate a defined level ofresistance to the energy flow which is being transmitted through theconductors 104 and 106.

Furthermore, while the exemplary embodiments discuss the use of“resistance segments,” the present invention may be practiced with aplurality of segments wherein each segment is defined to exhibit a unitvalue which is representative of a specified energy transmissioncharacteristic other than resistance to energy flow. Additionally,discussion below with regard to the exemplary embodiments of detectingor measuring “changes in resistance” is equally applicable to detectingand measuring a change in the specified energy transmissioncharacteristic.

Referring still to FIG. 1, the resistance segments 110A-110D of thefirst conductor 104 are operatively connected in series with oneanother. Likewise, the resistance segments of the second conductor 106are operatively connected in series with one another. It is noted that,while the exemplary embodiment of the network 100 is shown using twoconductors 104 and 106 with each having four-resistance segments110A-110D and 112A and 112D respectively, the invention may be practicedwith other combinations of conductors and resistance segments as shallbe discussed in greater detail below.

A plurality of identity groups 114A-114D are formed of laterallyadjacent resistance segments 110A-110D and 112A-112D respectively. Thus,identity group 114A comprises resistance segments 110A and 112A,identity group 114B comprises resistance segments 110B and 112B and soon.

Referring to FIG. 2, and using an example of conductors 104 and 106comprising conductive traces or other electrically conductive members,the resistance segments 110A-110D and 112A-112D are assigned exemplaryunit resistance values, in this case expressed in the unit ohms forelectrical resistance. The assigned, or defined unit resistance valuesare as shown in FIG. 2 with resistance segment 110A having a unitresistance value of 1 ohm, resistance segment 112A has a unit resistancesegment of 4 ohms, and so on. Further, each identity group may beidentified by a concatenated digit string which is representative of theactual or normalized unit resistance values contained therein. Thus,identity group 114A may be represented by the digit string “14” based onthe unit resistance values for resistance segments 110A and 112A.Similarly, identity group 114B may be represented by the digit string“23”, identity group 114C by the digit string “32” and identity group114D by the digit string “41.”

It is noted that the concatenated digit string for each identity group114A-114D is a unique number in comparison with the concatenated digitstrings for every other identity group within the network 100. Further,it is noted that the ratios of the unit resistance values within a groupidentity are likewise unique. For example, the ratio of unit resistancevalues in identity group 114A is 1:4 or 0.25. In comparison, the ratiofor identity group 114B is 2:3 or 0.667, for identity group 114C is 3:2or 1.5 and for identity group 114D is 4:1 or simply 4. The identity ofsuch ratios, as well as the uniqueness each of the various ratios,assist in detecting, locating and quantifying a physical phenomena asshall become more apparent below.

Referring to FIG. 3, a network such as described above is incorporatedinto a structure 120 which, in the exemplary embodiment, is shown as aconduit 122 such as, for example, a part of a pipeline for carrying afluid medium. The network 100 is formed on the interior surface 124 ofthe conduit 122, although other locations, including the exterior of thepipeline, are also suitable. Generally, the network 100 may be formed onthe surface of, or embedded within, any of a number of differentstructures, which may be referred to more generically as a substrate.

In the case of a pipeline or conduit 122, it may be desirable to detectstrain or deformation within the structure 120 so as to determinepotential failures which, in this case, may result in leakage of fluidfrom the conduit. Thus, for example, if the conduit 122 exhibitsdeformation or strain in an area associated with identity group 114B,resistance segments 110B and 112B, which are coupled with the surface124 of the conduit 122, will likewise exhibit the strain or deformation.If the conductors 104 and 106 are electrical type-conductors, theresistance segments 110B and 112B will exhibit a change in resistivityupon experiencing an induced strain. Thus, a change in resistancemeasured across the conductors 104 and 106 indicates a deformation inthe structure. It is noted that if the conductors are positioned closelyenough, a substantial deformation in the structure 120 to which they areattached should induce strain in both conductors 104 and 106. Thus,certain anomalies wherein a resistance change in one conductor 104 butnot another 106 may be substantially accounted for.

It is also noted that if the conductors 104 and 106 are of a differenttype of energy transmitting medium, such as, for example, opticalfibers, some other property will exhibit a change, such as a phasechange of the light signal traveling through optic fibers, uponexperiencing a strain therein.

Furthermore, while the exemplary embodiments set forth herein aredescribed in terms of detecting strain or transformation, other physicalphenomena may be detected, located and quantified. For example, thephysical phenomena may include changes due to temperature, corrosion,wear due to abrasion, chemical reactions or radiation damage asexperienced by the conductors.

Still using electrical conductors 104 and 106 as an example, the changein resistivity in each resistance segment 110B and 112B will be afunction of the unit resistance values respectively associatedtherewith. By determining the ratio of the change in resistance measuredby a receiver 108 through each of the conductors 104 and 106, thelocation of the strain may be determined.

For example, referring back to FIG. 2, a strain induced in theresistance segments 110B and 112B of identity group 114B will result ina change of resistivity in each conductor 104 and 106. It is noted thatupon initial implementation of the network 100 the overall resistance ofa conductor 104 and 106 may be measured and utilized as a baselinevalue. Any subsequent measurements of resistance may then be compared tothe baseline value to detect whether a change in resistance has occurredor not. The conductors 104 and 106 may be checked for resistance changesat a predetermined sample rate, such as, for example, once per second.Of course other sample rates may be utilized according to specificapplications and monitoring requirements.

It may be the case that once a change in resistance has been detectedthat the measured value of resistance may not return to its originalbaseline value. For example, a change in resistance may be due to apermanent deformation in an associated structure. Thus, it may berequired to set a new baseline value (or re-zero the values) of theoverall measured resistance in the conductors 104 and 106 after thedetection of a change in resistance.

The measured change in resistance detected in the conductors 104 and 106is a function of the unit resistance values of the individual resistancesegments 110B and 112B (e.g., it is a function of, in this exampleproportional to, the values of 2 ohms and 3 ohms respectively). Thus, bytaking the ratio of the change in resistance measured by the receiver(i.e., ΔR₁₀₄/ΔR₁₀₆, where ΔR is the change in resistance for thespecified conductor), the ratio may be compared to the ratios of theunit resistance values of each identity group 114A-114D to determine thelocation of the strain. In this case, strain exhibited in the regionencompassed by identity group 114B will exhibit itself as a change inresistance in both conductors 104 and 106, the ratio of which changewill be a function of the ratio 2:3 or 0.667 which is equal to the ratioof the unit resistance values thereof. The detection of strain ordeformation within identity groups 114A, 114C or 114D would likewiseyield, with regard to the change in resistance in the conductors 104 and106, functions of the ratios 0.25, 1.5 and 4 respectively.

Having located the area of deformation (e.g., within identity group114B) the magnitude of the strain may then be calculated. As will beappreciated by one of ordinary skill in the art, the change inresistance measured by the receiver 108 for a particular conductor 104or 106 is a function of the unit value resistance associated with theresistance segment (e.g. 110B or 112B) in which the strain was detected.Thus, by knowing the unit value of resistance for a particularresistance segment in which strain has been detected, the amount ofchange in resistance exhibited by a conductor and the relationshipbetween strain and resistance for a conductor of a given configurationand material composition, one can calculate the amount of strainexhibited by the conductors 104 and 106 and thus the amount of straininduced in any associated structure 120 to which they are attached.

For example, having located a strain in identity group 114B, andassuming the use of electrical traces for conductors 104 and 106 andassuming linear proportionality between change in resistance and unitresistance, one could determine the magnitude of the strain using thefollowing equations:${DEFORMATION} = {\frac{{\delta ɛ}(R)}{\delta(R)}\frac{\Delta\quad R_{104}}{2}}$for the strain exhibited in conductor 104, and;${DEFORMATION} = {\frac{{\delta ɛ}(R)}{\delta(R)}\frac{\Delta\quad R_{106}}{3}}$for the strain exhibited in conductor 106 where ε(R) is represents therelationship between resistance and strain for a given resistancesegment, ΔR represents magnitude of the change of resistance measured ina given conductor and wherein the numeral denominator represents theunit resistance value for the particular resistance segment in whichstrain was detected (i.e., the “2” in the first equation is forresistance segment 110B, and the “3” in the second equation is forresistance segment 112B).

As has been noted above, one embodiment may include the use ofconductive traces for conductors 104 and 106. Referring to FIGS. 4A and4B, a partial cross-sectional view is shown of conductors 104 and 106utilizing conductive traces according to one embodiment. As is indicatedin FIG. 3, FIG. 4A is a view depicting the resistance segments inidentity group 114C while FIG. 4B is a view depicting the resistancesegments in identity group 114D.

The conductors 104 and 106, shown as conductive traces, may be attachedto a structure 102, such as the conduit 122, by a thermal spray process.In order to apply the conductive traces to a structure 120, includingone in which the surface may be degraded and/or conductive, it may bedesirable to provide an insulative layer 130 directly on the surface 124of the structure (e.g., the conduit 122). The insulative layer 130 keepsthe conductors 104 and 106 from forming an electrical connection withthe structure 120, and also provides a uniform surface on which to formthe conductors 104 and 106. One insulative layer 130 may be formed andsized such that all of the conductors 104 and 106 may be formed thereonor, alternatively, an individual layer 130 may be formed for eachindividual conductor 104 and 106 as may be desired. A second insulativelayer 132 may be formed to encompass or encapsulate the conductors 104and 106 from each other and from the surrounding environment. It isnoted, however, that if physical phenomena such as corrosion or abrasionis being detected, located and/or quantified, that the second insulativelayer 132 would not be needed.

Such an embodiment as shown in FIGS. 4A and 4B may include, for example,an insulative layer 130 formed of alumina, conductive traces ofnickel-aluminum, and a second insulative layer 132 of alumina. Othermaterials may also be suitable such as, for example, copper or otherconductive materials for the conductors 104 and 106. Likewise othermaterials may be utilized in forming the insulative layers 130 and 132.

An embodiment such as that shown in FIGS. 4A and 4B may be formed bythermal spraying of the insulative layers 130 and 132 and/or theconductive traces (which form the conductors 104 and 106). In oneexemplary embodiment, a thermally sprayed insulative layer 130 may beapproximately 0.5 inches wide and 0.12 to 0.15 inches thick. Aconductive trace acting as a conductor 104 or 106 may be formed with awidth of approximately 0.3 inches and a thickness of approximately 0.007inches. One such exemplary conductive trace was formed on the interiorof an eight inch long piece of square tubing and exhibited an electricalresistance of 4.1 ohms under no-load conditions. The same conductivetrace exhibited a change in resistance to approximately 38 ohms when thetubing was subjected to three-point bending with a loading ofapproximately 40,000 pounds. The conductive trace returned to 4.1 ohmsupon removal of the three-point bending load.

An exemplary thermal spraying device which may be used in conjunctionwith the application such insulative layers 130 and 132 and/orconductors 104 and 106 is disclosed in pending U.S. patent applicationSer. No. 10/074,355 entitled SYSTEMS AND METHODS FOR COATING CONDUITINTERIOR SURFACES UTILIZING A THERMAL SPRAY GUN WITH EXTENSION ARM,filed on Feb. 11, 2002 and which is assigned to the assignee of thepresent invention, the entirety of which is incorporated by referenceherein.

Referring briefly to FIG. 5, the conductors 104 and 106, when in theform of electrical conductive traces, may be formed by building upindividual layers 140A-140G until a desired thickness or height of theconductors 104 and 106 is obtained. Likewise, if so desired or needed,the insulative layers 130 and 132 may be layered to obtain a desiredthickness or height. Further, if so needed, a bonding agent or bondinglayer 134 may be used between the insulative layer and a surface 136 ofthe structure 120 if the surface exhibits a degree of degradation.

As can be seen by comparing the conductors 104 and 106 from FIG. 4A toFIG. 4B the conductors 104 and 106 may vary in cross sectional area fromone resistance segment to another (i.e., from 110C to 10D and from 112Cto 112D). The change in cross-sectional area of the conductors 104 and106 may be effected by varying their width (such as shown), their heightor some combination thereof. Of course other cross-sectional areas arecontemplated and the variance thereof may depend on other variables,such as for example, a diameter of the cross-sectional area.

Changing the cross-sectional area of the conductors 104 and 106 is oneway of defining unit resistance values for the plurality of resistancesegments 110A-110D and 112A-112D. Alternatively, the unit resistancevalues may be defined by utilizing different materials or varying thematerial compositions for the individual resistance segments 110A-110Dand 112A-112D. For example, a first resistance segment 110A may beformed of a first material exhibiting a first resistivity while the nextadjacent resistance segment 110B may be formed of another material whichexhibits a different resistivity. Alternatively, some property of thematerial, such as, for example, porosity, may be altered from oneresistance segment 110A to the next 1110B. For example, in thermallysprayed conductive traces, the unit resistance may also be a function ofthe size of the droplets being sprayed to form the trace, as well asother properties associated with the bonding surfaces of such droplets.

Referring back now to FIGS. 1 and 2, as noted above, the network 100shown is exemplary, and numerous variations may be made in order toimplement the network 100 in specific systems or structures. Forexample, if such a network installed into a structure such as pipeline,or a section thereof, more conductors than just two may be desired so asto refine the resolution of the network 100 for locating a strain orother physical phenomena detected thereby.

Such a pipeline may include multiple lengths of twenty miles or longerbetween which lengths structures known as “pig traps” (for insertion andremoval of “pigs” as is known in the art) may be formed. Thus, it may bedesirable to extend a plurality of conductors for a length as great astwenty miles or more. Thus, using a twenty mile section of a pipeline asan example, it will become desirable to locate the situs of the detectedphysical phenomena within a given range of distance along that twentymile section. Such a network 100 becomes much more valuable when theresolution with regard to locating the situs of the physical phenomenais refined to within a physically searchable distance such as, forexample, tens of feet.

In determining how many conductors should be used for such anapplication, the number of resistance segments formed in a givenconductor and how many different unit resistance values may be assignedto the plurality of conductors must be known. It is noted that thenumber of different unit resistance values which may be used willdetermine the number base (i.e., base 10, base 8, etc.) will be used innumerically representing the unit resistance values of each resistancesegment.

With respect to the number of resistance segments, considering adistance of twenty miles and assuming a resolution of approximately plusor minus twenty feet, one may determine that there will be 5,280segments in a given conductor (i.e., (20 miles×5,280 feet/mile)/20feet/segment=5,280 segments).

To determine the number of different unit resistance values which may beused in a given conductor, the uncertainty with respect to theconstruction of the resistance segments must be considered. For example,considering electrical traces being used as conductors, the uncertaintyassociated with the cross-sectional area of the trace must beconsidered. The uncertainty in cross-sectional area of a conductivetrace may include combined uncertainties of both width and thickness (orheight). Additionally, uncertainty may be affected by the mode ofconstruction of the conductive traces. For example, building up aconductive trace by thermally spraying multiple layers (such as in FIG.5) has an affect on the overall certainty of the resultant height aswill be appreciated by those of ordinary skill in the art. Such valuesof uncertainty may be determined through statistical analysis,experimentation or a combination thereof as will also be appreciated bythose of ordinary skill in the art.

For sake of example, considering the uncertainty in the cross-sectionalarea of a conductive trace to be less than 10%, say for example 9.9%,one may determine that the maximum number of useful unit resistancevalues which may be assigned to the individual resistance segments of aconductor is ten (i.e., Max. #<100/9.9≦10.1). Thus, the base number forthe above example would be base ten, or in other words, ten differentunit resistance values may be assigned to resistance segments of aconductor.

Knowing that 5,280 resistance segments will be used, and that tendifferent unit resistance values will be used, one may determine thenumber of conductors which will be needed to provide 5,280 uniqueconcatenated digit strings for the identity groups. It is desirable thatthe unique concatenated digit strings each represent a prime numbersince the use of a prime number guarantees the ratios of all the unitresistance values represented thereby will be unique. For example,considering a four digit prime number of “ABCD”, each ratio of A:B, A:C,A:D, B:C, B:D and C:D will be unique. It is noted that no concatenateddigit string should include a zero digit, as an electrical trace may notbe constructed to include a resistance segment having a unit resistancevalue of zero.

The number of prime numbers available for a particular digit string maybe determined using one or more of various algorithms or databases knownand available to those of ordinary skill in the art. For example, theUniversity of Tennessee at Martin has published various lists of primenumbers including a list of the first 100,008 prime numbers (alsoreferred in the publication as “small primes”). Such a list allows forthe determination of the number of nonzero primes up to six digits inbase ten. Using such a database or publication it may be determined thatthe number of five digit nonzero primes is 6,125. Thus, five conductorsmay be used to form a network of 5,280 resistance segments per conductor(and thus 5,280 identity groups with associated concatenated digitstrings) with each resistance segment being twenty feet long.

The operation of the five-conductor network would then be similar tothat described above with respect to FIGS. 1 through 3 whereinresistance changes would be detected with associate ratios of suchresistance changes being compared to a database of ratios associatedwith the 5,280 identity groups to locate a situs of strain or some otherphysical phenomena. Of course, it is noted that, while the use of afive-conductor network may be adequate for coding resolution issuespresented above, it may be desirable to provide one or more conductors(e.g., a six- or seven-conductor network) for fault tolerance purposes.Thus, with fault tolerance, even if a conductor within the networkfails, adequate coding capability will remain in place to sufficientlyidentify, locate and quantify a physical phenomena.

It is also noted that the resolution may be improved over a given lengthby either improving the uncertainty associated with the construction ofthe conductors, or by including a greater number of conductors. Forexample, the number of conductors in the above scenario may be increasedto obtain a resolution of plus or minus ten feet, five feet or less ifso desired.

Referring back to FIG. 5, it is noted that either in conjunction with anetwork 100 (FIG. 1), or independent therefrom, conductors 104 and 106may be attached to a structure 120 for use in carrying other signals andmeasuring other values associated with the structure 120. For example,one or more sensors 150 or other microinstrumentation may be attachedto, or embedded in, a conductor 104 and 106 for purposes of measuring ordetecting pressure, temperature, flowrate, acoustic signals, chemicalcomposition, corrosion or data transmission anomalies. Conductors 104and 106, such as the conductive traces described above herein, have theability to extend for substantial distances (e.g. several miles) withoutsubstantial degradation in signal transmission. Thus, one or more ofsuch conductors may also be utilized as a communications link if sodesired.

As shown in FIG. 6, such traces or other conductors 104 and 106 may beinstalled in a conduit 122 or other structure in a predeterminedgeometric arrangement so as to detect strain or some other physicalphenomena at various locations within the structure. For example, FIG. 6shows a plurality of conductors 104 and 106 angularly displaced about acircumference of the conduit 122 and configured to coextensively andlongitudinally extend with the length of the conduit 122. Such anarrangement allows for detection of a strain or other physicalphenomenon which occurs on only a portion of the structure.

Thus, a plurality of networks may be disposed on a single structure.Alternatively, individual conductors might be spaced about thecircumference with each carrying one or more sensors therewith. Ofcourse other geometrical configurations may be utilized. For example,one or more networks (or alternatively, individual conductors) may beconfigured to extend from one end of a conduit 122 to another in ahelical pattern about a circumference thereof.

FIG. 7 is block diagram of a system including a computing system and anetwork system cooperatively configured to identify and locate adeflection in a structural member, in accordance with an embodiment ofthe present invention. The network 100 is cooperatively arranged along astructural member (e.g., pipe, conduit, or other deflectable member) inaccordance to one or more of the various embodiments previouslydescribed. The transmitter 102 and receiver 108 are coupled to andcontrolled by computing system 198 and may further include one or morerelay or networking elements (not shown) for routing signals fromspatially separated transmitter 102 and/or receiver 108 to the computingsystem 198.

Computing system 198 illustrates a suitable program-executingenvironment for locating a deformation of a structural member, inaccordance with one or more embodiments of the present invention.Computing system 198 is only one example of a suitable computing systemand is not intended to be limiting of the scope of the variousembodiments of the present invention. While the present illustration ofcomputing system 198 includes various computing options and peripherals,an embedded computing implementation wherein the computing system isconfigured and functions without providing any general user interface isalso contemplated. The illustrated computing system should not beinterpreted as having any requirement relating to any one of thecomponents illustrated in the exemplary computing system 198.

One or more of the various embodiments of the present invention may bedescribed in the context of computer-executable instructions, such asprogram modules being executed by a computer. Generally, program modulesinclude routines, programs, objects, components, data structures, etc.that perform particular tasks. Those of ordinary skill in the art willappreciate that the various embodiments of the present invention may bepracticed with other computing configurations, including hand-helddevices, multiprocessor devices, microprocessor-based devices,microcontroller-based devices or, as mentioned, embedded computingsystems. Furthermore, one or more elements of the computing system maybe linked through a communication network (not shown) and may further bearranged in a distributed computing environment wherein portions of thecomputing functionality may be partitioned and distributed on a firstcomputing environment while a second portion may be distributed on asecond computing environment, an example of which may include aclient-server partitioning of computing resources.

An exemplary computing system 198 includes a general purpose computer200 including a processor 202, a system memory 204, and a system bus 206for operatively coupling the various system components to allowaccessing by processor 202. Computer 200 typically includes a variety ofcomputer-readable media which, by way of example and not limitation, mayinclude storage media and communication media. System memory 204includes computer-readable media in the form of volatile and/ornonvolatile memory respectively illustrated as random access memory(RAM) 208 and read only memory (ROM) 210. Nonvolatile memory (ROM) 210may further include a basic input/output system (BIOS) 212 containingroutines for transferring information between elements within computer200. Volatile memory (RAM) 208 typically contains data and programmodules that are readily accessible to processor 202. By way of exampleand not limitation, volatile memory (RAM) 208 is illustrated asincluding an operating system 214, application programs 216, otherprogram modules 218, and program data 220.

Computer 200 may also include other removable/nonremovable,volatile/nonvolatile media for storing computer-readable/executableinstructions and/or data. By way of example and not limitation, computer200 may further include a hard disk drive 222 and may be configured toread or write to nonremovable nonvolatile media 222, one or moreremovable nonvolatile disk drives 224, 226 which may be configured tointerface with removable, for example, magnetic media 228 and/orremovable optical media 230. Other removable/nonremovable,volatile/nonvolatile computer storage media may also be used and mayinclude, but are not limited to, tape cassettes, memory cards, disks,solid state memory devices, and the like. The aforementioned mediadevices are coupled to the system bus 206 through one or more interfaces232, 234.

Input devices may also be included within computing system 198 whichenable, for example, a user to enter commands and information intocomputer 200 through input devices such as a keyboard 236 and/or apointing device 238. These and other input devices are often connectedto the processor 202 through a user input interface 240 that is coupledto the system bus 206 but may be coupled to other interfaces or busstructures such as parallel ports or universal serial bus (USB) ports.Computing system 198 may further include output devices such as adisplay 242 connected via a video interface 244 to the system bus 206.Computing system 198 may further include other output devices such asprinters 246 and speakers 248 which may be connected to the system bus206 through an output peripheral interface 250. Network 100 for locatingthe deformation of a structure is coupled to computer 200 through aninput/output interface 262 which couples the network 100 to the systembus 206 thereby enabling access and control of network 100 by processor202.

As stated, computer 200 may operate in a networked environment usinglogical connections to one or more remote computers, such as a remotecomputer 252. Remote computer 252 may be a computer similar to computer200 containing similar elements. The logical connections betweencomputer 200 and remote computer 252 are depicted to include one or moreof a local area network 254 and/or a wide area network 256, coupled tosystem bus 206 through one or more network interfaces 258 or modems 260.While the various elements of computing system 198 may be illustrated tobe inclusive or exclusive of computer 200, such a representation isillustrative and not to be considered as limiting.

Although many other internal components of computer 200 are not shown,those of ordinary skill in the art will appreciate that such componentsand the interconnections and interfaces are known by those of ordinaryskill in the art. Accordingly, additional details and specifics ofcomputer 200 are not further disclosed in connection with the variousembodiments of the present invention.

FIG. 8 illustrates an overall flowchart of an embodiment of the presentinvention. A structural defection locator method locates a specificdeformed portion or segment of a structure such as a pipeline, whenexecuted in conjunction with a network 100 (FIG. 7) as further describedhereinabove. Accordingly, the present method determines the location ofa change in a characteristic of a segment extending along a structure,an example of which is a change in electrical resistance at a locationalong the length of a structural member such as a pipeline. A locationis identified by determining changes in the resistance along the variousconductors extending throughout the length or partial length of apipeline and then identifying unique ratios corresponding to specificsegments within an identity group.

Specifically, a deflection locator method 300 is exemplary illustratedherein with respect to electrical resistance measurements and changesbut may be further extended, as described hereinabove, to otherdetectable and measurable phenomenon that may exhibit changes inconjunction with deformation. Deflection locator method 300 acquires 302baseline resistance readings of the conductors 104, 106 (FIG. 7)extending along the length, for example, of a pipeline structure.Acquisition of baseline resistance readings continues until a query 304determines that all conductors are baselined. Determination of acompletion of the baselining may involve the establishment of a baselinethreshold wherein multiple measurements are iteratively taken until suchtime as the variations in the measurements is within a tolerance or lessthan a threshold. The specifics relating to such statistical baseliningand deviations associated therewith may be determined through ad hoc orother statistical methodologies.

Upon completion of acquisition of baselined resistance readings for eachof the conductors within network 100 (FIG. 7), the baseline resistancereadings or measurements for each of the conductors maybe furthernominalized by averaging 310 of the baseline resistance readings. Theaveraged baseline readings for each conductor are stored 312 as programdata 220, within computer 200 (FIG. 7).

Once the baselining process has been performed, a monitoring processmeasures 320 a current resistance value for each of the conductors ofnetwork 100 (FIG. 7). The measuring process continues until eachconductor has been measured as determined by a query 322. Changes in theresistance (dR) from the baseline readings are calculated 330 for eachof the conductors of network 100 (FIG. 7). If the change in resistancedoes not exceed a threshold as determined by a query 340, then theprocessing returns to measuring 320 the present resistance and themonitoring process repeats. If the calculated change in resistanceexceeds a threshold as determined by query 340, then the deformationregion is located 350 using the method and technique describedhereinabove, namely the identification of the specific ratioscorresponding to a uniquely identifiable identity group 114 (FIG. 1).The threshold may be determined through ad hoc or other statisticalmethodologies.

It is noted that the exemplary embodiments set forth above may beincorporated into any number of structures including stationarystructures as well as mobile structures. For example, such a systemcould be employed in bridges, dams, levees, containment vessels,buildings (including foundations and other subsurface structures),aircraft, spacecraft, watercraft, and ground transport vehicles orvarious components thereof. Indeed, the system may be utilized withvirtually any structure wherein detection, location and quantificationof a specified physical phenomena is required.

While the invention may be susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and have been described in detail herein.However, it should be understood that the invention is not intended tobe limited to the particular forms disclosed. Rather, the inventionincludes all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the followingappended claims.

1. A method of locating deformation of a structure, comprising:baselining a defined energy transmitting characteristic for each of aplurality of laterally adjacent conductors attached to a structure, eachof the plurality of conductors including a plurality of segments coupledin series and having an associated unit value representative of thedefined energy transmitting characteristic, the plurality of laterallyadjacent conductors including a plurality of identity groups, eachidentity group including at least one of the plurality of segments fromeach of the plurality of conductors; monitoring each of the plurality ofconductors for a difference in the defined energy transmittingcharacteristic when compared with a baseline energy transmittingcharacteristic for each of the plurality of conductors; and calculatinga location of the deformation along the structure when the differenceexceeds a threshold.
 2. The method of claim 1, wherein baseliningfurther includes measuring the defined energy transmittingcharacteristic for each of a plurality of laterally adjacent conductorsattached to a structure.
 3. The method of claim 2, wherein baseliningfurther includes: iterating measuring the defined energy transmittingcharacteristic of each of a plurality of laterally adjacent conductorsattached to the structure; and storing a plurality of measurements foreach iteration of measuring the defined energy transmittingcharacteristic of each of the plurality of laterally adjacentconductors.
 4. The method of claim 3, further comprising averaging theplurality of measurements of each of the plurality of laterally adjacentconductors to define the baseline energy transmitting characteristic foreach of the plurality of conductors.
 5. The method of claim 1, whereincalculating a location comprises comparing a first change in the definedenergy transmitting characteristic in at least one conductor of theplurality of conductors with a second change in the defined energytransmitting characteristic in at least one other conductor of theplurality of conductors.
 6. The method of claim 5, wherein calculatingfurther comprises determining a specific one of the plurality ofidentity groups from which the first change in the defined energytransmitting characteristic and second change in the defined energytransmitting characteristic were initiated.
 7. The method of claim 6,wherein determining a specific identity group includes determining aratio of the first change in the defined energy transmittingcharacteristic with respect to the second change in the defined energytransmitting characteristic.
 8. The method of claim 7, whereindetermining a specific identity group further includes comparing theratio of the first and second changes in the defined energy transmittingcharacteristic to a plurality of predetermined ratios, wherein theplurality of predetermined ratios includes ratios of unit values of theplurality of laterally adjacent segments within each of the plurality ofidentity groups.
 9. A system for locating deformation of a structure,comprising: a network configured for attachment to a structure includinga plurality of laterally adjacent conductors, each of the plurality ofconductors including a plurality of segments having an associated unitvalue representative of a defined energy transmission characteristic,the plurality of laterally adjacent conductors including a plurality ofidentity groups, each identity group including at least one of theplurality of segments from each of the plurality of conductors, whereineach segment within an identity group exhibits an associated unit valuesuch that the unit values of each identity group may be represented by aconcatenated digit string of the unit values and wherein each identitygroup exhibits a unique concatenated digit string relative to each otheridentity group; and a computing system configured to baseline a definedenergy transmitting characteristic for each of a plurality of laterallyadjacent conductors, monitor each of the plurality of conductors for adifference in the defined energy transmitting characteristic whencompared with a baseline energy transmitting characteristic for each ofthe plurality of conductors, and calculate a location of the deformationalong the structure when the difference exceeds a threshold.
 10. Thesystem of claim 9, wherein the computing system is further configured tomeasure the defined energy transmitting characteristic for each of aplurality of laterally adjacent conductors attached to a structure. 11.The system of claim 10, wherein the computing system is furtherconfigured to iterate measuring the defined energy transmittingcharacteristic of each of a plurality of laterally adjacent conductorsattached to the structure, and store a plurality of measurements foreach iteration of measuring the defined energy transmittingcharacteristic of each of the plurality of laterally adjacentconductors.
 12. The system of claim 11, wherein the computing system isfurther configured to average the plurality of measurements of each ofthe plurality of laterally adjacent conductors to define the baselineenergy transmitting characteristic for each of the plurality ofconductors.
 13. The system of claim 9, wherein the computing system isfurther configured to compare a first change in the defined energytransmitting characteristic in at least one conductor of the pluralityof conductors with a second change in the defined energy transmittingcharacteristic in at least one other conductor of the plurality ofconductors.
 14. The system of claim 13, wherein the computing system isfurther configured to determine a specific one of the plurality ofidentity groups from which the first change in the defined energytransmitting characteristic and second change in the defined energytransmitting characteristic were initiated.
 15. The system of claim 14,wherein the computing system is further configured to determine a ratioof the first change in the defined energy transmitting characteristicwith respect to the second change in the defined energy transmittingcharacteristic.
 16. The system of claim 15, wherein the computing systemis further configured to compare the ratio of the first and secondchanges in the defined energy transmitting characteristic to a pluralityof predetermined ratios, wherein the plurality of predetermined ratiosincludes ratios of unit values of the plurality of laterally adjacentsegments within each of the plurality of identity groups.
 17. Acomputer-readable medium having computer-executable instructions forlocating a deformation of a structure, the instructions for performingthe acts of: baselining a defined energy transmitting characteristic foreach of a plurality of laterally adjacent conductors attached to astructure, each of the plurality of conductors including a plurality ofsegments coupled in series and having an associated unit valuerepresentative of the defined energy transmitting characteristic, theplurality of laterally adjacent conductors including a plurality ofidentity groups, each identity group including at least one of theplurality of segments from each of the plurality of conductors;monitoring each of the plurality of conductors for a difference in thedefined energy transmitting characteristic when compared with a baselineenergy transmitting characteristic for each of the plurality ofconductors; and calculating a location of the deformation along thestructure when the difference exceeds a threshold.
 18. Thecomputer-readable medium of claim 17 having further computer-executableinstructions, wherein baselining further includes measuring the definedenergy transmitting characteristic for each of a plurality of laterallyadjacent conductors attached to a structure.
 19. The computer-readablemedium of claim 18 having further computer-executable instructions,wherein baselining further includes: iteratively measuring the definedenergy transmitting characteristic of each of a plurality of laterallyadjacent conductors attached to the structure; and storing a pluralityof measurements for each iteration of measuring the defined energytransmitting characteristic of each of the plurality of laterallyadjacent conductors.
 20. The computer-readable medium of claim 19 havingfurther computer-executable instructions, further comprising averagingthe plurality of measurements of each of the plurality of laterallyadjacent conductors to define the baseline energy transmittingcharacteristic for each of the plurality of conductors.
 21. Thecomputer-readable medium of claim 17 having further computer-executableinstructions, wherein calculating a location comprises comparing a firstchange in the defined energy transmitting characteristic in at least oneconductor of the plurality of conductors with a second change in thedefined energy transmitting characteristic in at least one otherconductor of the plurality of conductors.
 22. The computer-readablemedium of claim 21 having further computer-executable instructions,wherein calculating further comprises determining a specific one of theplurality of identity groups from which the first change in the definedenergy transmitting characteristic and second change in the definedenergy transmitting characteristic were initiated.
 23. Thecomputer-readable medium of claim 22 having further computer-executableinstructions, wherein determining a specific identity group includesdetermining a ratio of the first change in the defined energytransmitting characteristic with respect to the second change in thedefined energy transmitting characteristic.
 24. The computer-readablemedium of claim 23 having further computer-executable instructions,wherein determining a specific identity group further includes comparingthe ratio of the first and second changes in the defined energytransmitting characteristic to a plurality of predetermined ratios,wherein the plurality of predetermined ratios includes ratios of unitvalues of the plurality of laterally adjacent segments within each ofthe plurality of identity groups.